Stem cell method preserves embryos

New process could solve ethical issue, but doubts remain

August 24, 2006|By Dennis O'Brien | Dennis O'Brien,Sun Reporter

Researchers in Massachusetts say they have produced human embryonic stem cell lines without destroying embryos, a potential key step in overcoming an ethical issue that has transformed stem cell research into a political battleground.

Reporting today in the British journal Nature, scientists from Advanced Cell Technology Inc. said they used techniques from a common genetic testing procedure to generate new lines of cultured embryonic stem cells while leaving the original embryo intact.

Critics say the team has not resolved the key issue in stem cell research because its method still involves manipulating - and possibly damaging - human embryos.

"They're still being treated as a means to an end, even if you're not destroying them," said Richard Doerflinger, deputy director for pro-life activities at the U.S. Conference of Catholic Bishops. "You shouldn't be manipulating or posing any risk of harm to unconsenting subjects for work that's of no benefit to them."

Supporters of the research also expressed skepticism. "It's not ready for prime time," said Dr. John Gearhart, who heads the cell engineering institute at the Johns Hopkins School of Medicine.

Embryonic stem cells are the building blocks of human tissue and have an ability to grow into any of the body's cell types. Some researchers also work on "adult" stem cells programmed to create specific tissues. Because adult stem cells do not have to be coaxed from embryos, they are not as controversial.

Since scientists learned how to culture embryonic stem cells in 1998, the cells have became a critical tool for researchers who hope to use them to replace tissues in patients suffering from fatal or crippling ailments such as cancer, Parkinson's disease and heart disease.

Typically, scientists culture embryonic stem cells in a process that begins by scraping away cells from developing embryos discarded by fertility clinics.

That process destroys the embryos, prompting opposition from the Roman Catholic Church and conservative Christian groups. Four years ago, that led the Bush administration to ban federal funding for research using stem cell lines created after Aug. 9, 2001.

The ban has prompted a scramble for alternative ways to develop stem cells. It has also prompted states including Maryland, California and New Jersey to fund their own stem cell research. And it has thrust an arcane branch of medical research into the center of a political storm.

In April, Maryland Gov. Robert L. Ehrlich Jr. signed a bill into law securing $15 million for stem cell research in Maryland, with no conditions on the research methods.

This fall, candidates here and elsewhere are being asked to explain their stands on stem cell research.

Lt. Gov. Michael S. Steele, unlike other major candidates in the race for the U.S. Senate seat being vacated by Democrat Paul S. Sarbanes, who is retiring, has qualified his support for stem cell research by limiting it to methods that don't destroy embryos.

A spokesman for Steele's campaign did not return phone calls yesterday to determine whether Advanced Cell's method would qualify for his support.

The company, which has executive offices in California and research facilities in Massachusetts, said it extracted cells from 16 embryos in their early stages, the same way that fertility clinics extract them for genetic testing during the early stages of embryo development.

The embryos were donated by couples at fertility clinics, the researchers said.

Culturing the cells in a dish, the scientists found in experiments that of the 91 cells extracted, two developed into stem cell lines.

They said they don't know whether their stem cell lines will be as capable as traditionally cultured stem cells of forming the different cell types that make up the human body.

The cells were extracted from eight- and 10-cell embryos that had been developing for two to three days. Years of experience with the same extraction process by fertility clinics shows that it doesn't harm the embryos, the researchers said.

Stem cell lines are usually cultured from the cells of embryos that have developed for five to seven days, and have reached the blastocyst stage.

Last fall, the Advanced Cell group reported using similar techniques to create a line of embryonic mouse stem cells. In those experiments, scientists said, they demonstrated no harm to the original embryo because a healthy mouse was born from it.

"No one knew when or if it could actually be done in humans. Only now does the technology exist to create embryonic stem cells without destroying human embryos," said Dr. Robert Lanza, the senior member of the research team.

Some experts said the work is a step in the right direction because it opens a door to the production of new and much-needed stem cell lines.

"This is a neat and unique way to work around the federal limitations," said Dr. Curt Civin, a cancer researcher at Hopkins who is working with a stem cell line from the University of Wisconsin that meets the president's criteria.

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